1. Technical Field of the Invention
This invention relates to a transferring apparatus for transferring a substrate, for example, semiconductor wafer, LCD substrate glass, etc. and also relates to a substrate processing apparatus and a substrate processing system both performing the cleaning operation etc. for these substrates.
2. Description of the Related Art
For instance, in the manufacturing process for semiconductor devices, there widely spreads a cleaning system where semiconductor wafers (will be referred xe2x80x9cwafersxe2x80x9d below) are cleaned by a cleaning liquid to remove various contamination adhering to the wafers, for example, particles, organic pollutant, metallic impurities, etc. Especially, there is widely used a cleaning system that includes a wet-type cleaning apparatus to dip wafers into the cleaning liquid for the cleaning process.
In general, the conventional cleaning apparatus is equipped with a cleaning bath fulfilling a cleaning liquid and a wafer guide for dipping the wafers into the cleaning bath. The wafer guide can move up and down between the inside of the cleaning bath and its upside along a vertical guide-Z shaft. After receipt of the wafers on the upside of the cleaning bath, the wafer guide is lowered into the cleaning bath to dip the wafers into the cleaning liquid for cleaning the wafers. The cleaning system equipped with a number of cleaning apparatuses mentioned above includes a loader/unloader part where the wafers are taken out of carriers and the wafers are accommodated into the carriers and a transferring apparatus that transfers the wafers between the loader/unloader part and the respective cleaning apparatuses. With the movement of wafer chucks along the respective cleaning apparatuses in the horizontal direction, the transferring apparatus can move the wafer chucks to the respective cleaning apparatuses. For example, after moving the wafer chucks to the upside of the cleaning bath of one cleaning apparatus, the wafer guide is elevated to carry out the delivery of the wafers.
In the cleaning system as above, it is necessary to detect the position (level) of the wafer guide in order to avoid a conflict between the wafer guide and the wafer chucks, for example. Therefore, the conventional system is provided, at respective levels along the above-mentioned guide-Z shaft, with a plurality of photoelectric sensors which detect the position of the wafer guide.
Accordingly, the conventional system has to establish a number of photoelectric sensors for every cleaning apparatuses, thereby causing the number of photoelectric sensors to be increased. Moreover, the increase in the number of photoelectric sensors is accompanied by frequent exchanges for parts and maintenance. Further, in case of the guide-Z shaft in the cleaning apparatus, every maintenance of the apparatus requires a cover etc. to be removed for completing a worker""s operation inside the apparatus, causing a troublesome operation.
Taking the above situation into consideration, an object of the present invention is to provide a transferring apparatus, a substrate processing apparatus and a substrate processing system, all of which allow of positional detection with ease and further facilitate the maintenance per se.
The first feature of the present invention resides in the provision of a transferring apparatus comprising at least two moving bodies with mutual interference potential, at least one moving body being driven by a motor; and a detection unit for detecting a position of the at least one moving body driven by the motor; wherein the detection unit includes an absolute encoder directly connected to the motor thereby to detect a revolution amount of a rotating shaft of the motor and further output a detection signal, a driver which receives the detection signal outputted from the absolute encoder thereby to output a positional information, and a controller which receives the positional information outputted from the driver thereby to judge the position of the moving body; and the controller controls in a manner that the moving bodies do not interfere with each other.
The second feature of the present invention resides in that the controller inputs an establishment for control program into the driver, while the driver controls the motor on a basis of the inputted establishment.
The third feature of the present invention resides in that the positional information outputted from the driver to the controller is identical to a sensor output which is generated by detecting whether the moving body is positioned in a predetermined area when the rotating shaft is rotating and/or stops rotating.
The fourth feature of the present invention resides in that the moving body is a substrate holder that moves while holding a substrate.
The fifth feature of the present invention resides in the provision of a substrate processing apparatus comprising: a transferring apparatus including: at least two substrate holders with mutual interference potential, at least one substrate holder being driven by a motor; and a detection unit for detecting a position of the at least one substrate holder; wherein the detection unit includes: an absolute encoder directly connected to the motor thereby to detect a revolution amount of a rotating shaft of the motor and further output a detection signal; a driver which receives the detection signal outputted from the absolute encoder thereby to output a positional information; and a controller which receives the positional information outputted from the driver thereby to judge the position of the substrate holder; wherein the controller controls in a manner that the substrate holders do not interfere with each other; and a processing bath for processing a substrate; wherein the substrate holder is movable to accommodate the substrate in the processing bath. The processing bath for processing the substrate is filled up with a processing liquid, for example, a cleaning liquid. The substrate holder can dip the substrate into the processing liquid in the processing bath because the holder is movable while holding the substrate.
The sixth feature of the present invention resides in the provision of a substrate processing apparatus which comprises:
a transferring apparatus including: at least one first substrate holder and at least one second substrate holder with mutual interference potential, the at least one first substrate holder being driven by a motor; and a detection unit for detecting a position of the at least one first substrate holder; wherein the detection unit includes: an absolute encoder directly connected to the motor thereby to detect a revolution amount of a rotating shaft of the motor and further output a detection signal; a driver which receives the detection signal outputted from the absolute encoder thereby to output a positional information; and a controller which receives the positional information outputted from the driver thereby to judge the position of the first substrate holder; wherein the controller controls in a manner that the substrate holders do not interfere with each other; and
a processing bath for processing a substrate;
wherein the first substrate holder is movable to accommodate the substrate in the processing bath, while the second substrate holder transfers the substrate thereby to give and receive the substrate to and from the first substrate holder; and
the second substrate holder is provided with drive means for moving the second substrate holder and the controller controls the drive means and the motor.
The seventh feature of the present invention resides in that the controller controls the drive means and the motor so that the first substrate holder does not collide with the second substrate holder.
The eighth feature of the present invention resides in the provision of an apparatus comprising a plurality of processing baths arranged in a horizontal direction to process a substrate therein; a plurality of first substrate holders provided for the plurality of processing baths respectively, the first substrate holders each moving between a position inside the corresponding processing bath and another position above the corresponding processing bath, in a vertical direction; a plurality of vertical movement units for moving the plurality of first substrate holders in the vertical direction; a second substrate holder which holds the substrate and moves to the horizontal direction above the plurality of processing baths; a horizontal movement unit for moving the second substrate holder in the horizontal direction; and a control unit which drives the vertical movement units and the horizontal movement unit so that the first substrate holders and the second substrate holder do not interfere with each other, thereby to move the first substrate holders and the second substrate holder.
The ninth feature of the present invention resides in that the substrate processing apparatus further comprises a plurality of position sensors which are arranged in respective positions along a horizontal movement of the second substrate holder thereby to detect various horizontal positions of the second substrate holder.
The tenth feature of the present invention resides in the provision of a transferring apparatus comprising a moving body driven by a motor, an absolute encoder directly connected to the motor and a controller for detecting a position of the moving body on a basis of a signal outputted from the absolute encoder. In this way, since the controller detects the position of the moving body on a basis of the signal outputted from the absolute encoder, it is possible to detect the position of the moving body with ease. Note, the substrate is illustrated by a substrate, such as semiconductor wafer, LCD substrate glass, etc. Besides these substrates, the substrate may be formed by any one of CD substrate, printed baseplate, ceramic substrate, etc.
The 11th. feature of the present invention resides in the provision of a transferring apparatus comprising a moving body driven by a motor and detector for detecting a position of the moving body, wherein the detector includes an absolute encoder directly connected to the motor thereby to detect a revolution amount of a rotating shaft of the motor and further output a detection signal, a driver which receives the detection signal outputted from the absolute encoder thereby to output a positional information, and a controller which receives the positional information outputted from the driver thereby to judge the position of the moving body.
Thus, in the detector, the absolute encoder detects the revolution amount of the rotating shaft of the motor thereby to output the detection signal, while e.g. the driver detects the position of the moving body on the ground of the above detection signal. Therefore, the detecting of the position of the moving body can be performed with ease. Again, the driver outputs the positional information to the controller, while the controller confirms whether e.g. the moving body is positioned as commanded. Here, as the absolute encoder outputs e.g. the absolute angle as the revolution amount of the rotating shaft, the driver can detect the position of the moving body on the ground of the output value of the detection signal. Moreover, owing to the adoption of the absolute encoder, even if e.g. a sudden power cut is caused, the position of the moving body could be memorized and therefore, there is no need to redo the initializing of the apparatus.